A Shape-Memory and Durable Transparent Polyacrylate Film Integrated by Soft-Rigid Chains

Flexible film in display requires multi-functional integration, such as stretchability, flexibility, abrasion resistance, transparency, and shape memory. In this paper, a reasonable design strategy of flexible polyacrylate (PA) film with high transparency, shape memory, excellent abrasion resistance and foldability is presented. The PA films are prepared by free radical polymerization of vinyl-terminated polyurethane (PU) prepolymer as a cross-linking agent and acrylate monomers in ultraviolet (UV) light. The various acrylate monomers in PA films with different functional groups (e. g. epoxy groups, benzene rings) provide soft-rigid chains and hydrogen bonds, which improve overall mechanical and optical properties. The experimental results also effectively demonstrate that after folding performance (500 cycles) or abrasion resistance (1000 cycles), the transparency of PA film remained above 91 %. In addition, the PA films with different folded shapes also prove excellent shape memory, which can fix the folded shape at low temperature and then return to the original shape at room temperature. Notably, the PA film is successfully applied to the curved touch screen through drawing, pattern decoding and image magnification in the simulation practical demonstration, fully revealing its great significance as a flexible substrate in the development of future flexible displays.